Study on the mitochondria Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis in testes of rats with varicocele

AIM: The cytoplasm Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis of testes in adult male rats with varicocele were observed to investigate the relationship between apoptosis and infertility. METHODS: Thirty-five healthy male Wistar rats were divided into two groups randomly: varicocele group (VG, n=20) and sham operation group (SOG, n=15). Bilateral testes were removed after ten weeks. One part of it was homogenized, the other part was performed for tissue sectioning. The atomic absorption method was used to detect the cytoplasm Ca 2+. The germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of Bcl-2/Bax was detected by immunohistochemical method. RESULTS: The cytoplasm Ca 2+ in testes of rats with varicocele was decreased obviously. The apoptosis indexes of germ cells and Bax expression in VG were significantly increased as compared with those in the SOG, while Bcl-2 expression was obviously decreased. CONCLUSION: The results showed that apoptosis was increased in testes of VG rats, suggesting that male infertility with varicocele may be caused by some apoptosis agents such as high temperature, testes toxin and oxygen free radical. The cytoplasm Ca 2+ and change of expression of Bcl-2/Bax may contribute to germ cell apoptosis and cause male infertility.